


A Complete Beginner’s Guide To Understanding Human Sexual Behaviour

by Anti_kate



Category: Good Omens (TV), Good Omens - Neil Gaiman & Terry Pratchett
Genre: A different sort of arrangement, Awkward First Times, M/M, PWP, PowerPoint presentations, Powerpoint with porn, Pre name change fic, They figure it out though, ancient babylon, idiots to lovers
Language: English
Status: Completed
Published: 2020-03-02
Updated: 2020-03-02
Packaged: 2021-02-27 20:49:04
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 6,354
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22992007
Author URL: https://archiveofourown.org/users/Anti_kate/pseuds/Anti_kate
Summary: “You can’t do it with humans, because of the Nephilim thing, right? And... you can’t do it with another angel, because they’re a bunch of feather-brained twits–“ at that Aziraphale looked as if he was about to argue, but Crawly kept talking, rapidly, “–which really only leaves demons, and I’m the only one you’ve got handy.”Aziraphale has a presentation, and Crawly helps him with his research.
Relationships: Aziraphale/Crowley (Good Omens)
Comments: 153
Kudos: 773
Collections: Courts GO Re-Reads, Ixnael’s Recommendations





	A Complete Beginner’s Guide To Understanding Human Sexual Behaviour

**Author's Note:**

> This is extremely silly. I hope you like it!  
> Two things of note: for the purposes of this fic, please imagine they’re not speaking English.  
> Also, apparently temple prostitution may or may not have been a thing in the cult of Ishtar.  
> Thank you to QuothARaven and D20OwlBear for beta-ing for me!

**Babylon, 600BC**

Crawly was hanging around the markets, causing the fruit in the most expensive stalls to go rotten, encouraging fleas to migrate from stray dogs to the prettiest of the women gossiping by the fountain, and upping the alcohol content in the beer in the hopes of starting a few fistfights as the day wore on. Then he felt that familiar crackling along his skin, as if something was sliding against his scales the wrong way. He looked around until, between colourful fabrics and pyramids of spices, he spotted a familiar white head moving down an alley. At least that made his day a bit more interesting. 

It wasn’t that Babylon was dull. Far from it—even if Crawly privately thought the city’s reputation for corruption and decadence was overblown. It was no more corrupt or decadent than anywhere else, really. Get enough people rubbing up against each other in one place and the sins committed themselves. Which meant there wasn’t much for him to do, demonically speaking. He didn’t have to convince anyone to do anything. 

He levered himself up from the mud-brick wall he’d been slouching against and trailed after the angel. He fully intended to slink up to him at the first opportunity, but before he could Aziraphale looked about, almost as if making sure no-one was watching, and then ducked into a building. Not just a building, but the Temple of Ishtar. _Interesting._

He sat down in the shade of one of the buildings where men were playing the game of 20 squares. To pass the time, he amused himself by feeding little trickles of irritation towards the losers, until one of them finally upended the board and stormed off. 

Sometime after the sun had set but the sky was still light, Aziraphale finally emerged from the temple, a papyrus scroll tucked under one arm. In the dusk, his hair seemed to glow. 

“Aziraphale!” Crawly called and to his delight, the angel started guiltily.

“Oh,” he said, with an expression something like pained horror. “It’s you.”

“And it’s good to see you again too,” Crawly said. Pained horror was at least better than being shoved away like a stray. “When was it last... Knossos?”

“Oh yes, you were encouraging all that bull leaping,” Aziraphale said, closing his hand firmly over the scroll under his arm, and glancing back at the building behind him. 

“Didn’t think I’d ever see _you_ in a place like the Temple of Ishtar.” Crawly circled about him, grinning cheerfully.

“Good lord,” Aziraphale muttered, starting off down a narrow alley at a surprisingly quick clip. “Were you watching me?”

“Course not. Just saw you then. So...” he kept pace with the angel through the winding streets. “What were you doing visiting that particular temple then?”

“If you must know, I was conducting research,” Aziraphale said, enunciating each word very clearly. 

“Is that what they’re calling it these days?”

“Crawly! Really!” The angel gave him one of those looks, and Crawly smiled even wider. 

“I’m not judging you, angel. It’s not in the job description. I’m just asking questions about why you’re hanging about in the temple of the goddess of fertility.”

Aziraphale huffed. “This conversation is most unseemly!”

“Is it?”

“It is!”

“Oh, were you ogling the bas reliefs? The ones with all the naked ladies? The ones with wings? Because I don’t know if you’ve noticed, but they seem to have a real thing about wings here,” Crawly continued, enjoying himself immensely. “You’d probably be very popular if you got them out, flashed a bit of pinion.”

“Crawly! No-one is ogling or flashing anything!” Aziraphale finally snapped. 

“What, then, were you trying to turn the temple prostitutes away from their lives of sin?”

Aziraphale shot him another look loaded with daggers, possibly poison-tipped ones.

“Of course not. The temple workers are well-paid, they are well-fed, and they’re safe. In fact, I encourage anyone I see on the streets plying their trade to seek employment there instead.”

“Ah,” Crawly suddenly felt vaguely ashamed, which was not something he enjoyed very much.

“It’s work,” Aziraphale continued, “as much as being paid to labour in the fields or cut stone in the quarry is work.”

“Yeah,” Crawly agreed. 

“Of course I do not agree with the worship of craven idols,” Aziraphale said, primly again, “and I did tell them that Ishtar is indeed a completely made-up false goddess and all that.”

“Course you did.”

Aziraphale had stopped walking, in front of a sandstone building much like all the other sandstone buildings in one of the city’s nicer areas. “If you’re done insulting me, this is where we part.”

“I’m not insulting you, I was just curious,” Crawly replied, and now, as he always was with Aziraphale, he found himself reluctant to let the conversation end. He softened, trying to find the right words to coax the angel towards something, anything, that would mean their meeting wasn't over. “Why don’t you come and get a drink with me and tell me about your ‘research’?” 

“I hardly think that’s appropriate,” Aziraphale said, as he always did, but he didn't move.

“Well, all right, I guess I should go and do something really demonic then." Crawly gave what he hoped was a suitably nefarious leer. “Something evil and wily, and you’ll be too busy doing ‘research’ to thwart me...”

“Oh good lord, come in then,” Aziraphale said, and ushered him into the house. “Consider yourself thwarted.”

The angel showed him through to a back room furnished with carpets and cushions and low seats. Rush lights and oil lamps burned in niches on the walls. Doors opened to a courtyard, and Crawly saw lush olive and pomegranate trees growing next to a small fountain. A cool breeze drifted in through the doors. 

Aziraphale bustled around, and a moment later he poured wine out of an earthenware jug and held the cup out to Crawly.

“If you must know, I have been asked to deliver a presentation to the angelic host, about,” here Aziraphale pursed his lips, “human sexual behaviour.”

Crawly almost spat out his wine. “What?” 

“Well, you see, a few decades ago I did one on food, which went down rather well. Dariel even tried some bread! Anyway, I managed to convince them that not all eating was gluttonous so...” Aziraphale sat on a cushion and took a careful sip of his own wine. He was always careful until the third or so cup, and then he was a sloppy drunk, spilling things everywhere. Crawly found watching him drink to be almost as much fun as drinking himself.

“They thought eating was bad?”

“Yes! I had to convince them I wasn’t being frivolous about providing food for the starving, that sort of thing. Anyway. They’ve asked me to explain coitus, and why humans are so very obsessed with it, and I thought Babylon was just the place to conduct my research.”

Coitus, Crawly thought, of course that was a word he’d use. 

“Anyway, the nice young ladies and men at the temple were very helpful. But of course, the problem is I have plenty of firsthand knowledge of food whereas. Well. Copulation is rather a mystery to me.”

There was a moment of silence, as Crawly considered the word copulation following on so quickly from the word coitus.

“Do you want to see it?” Aziraphale asked abruptly, plucking nervously at his tunic. 

“See... it...” Crawly echoed.

“My presentation? Perhaps you can give me some tips.” He didn’t wait for an answer, just waved his hand and then one of the walls was replaced with a large glowing square. 

He lifted his hand again and golden text appeared over the wall. _A Complete Beginner’s Guide to Understanding Human Sexual Behaviour,_ it read. Beneath that, in smaller letters: _By the Principality Aziraphale, Guardian of the Eastern Gate._

“Been a while since you guarded anything,” Crawly muttered. Aziraphale pretended not to hear him, and waved his hand once more. Another line of text appeared: _Please save all questions and comments for the end of this presentation._

“Thank you for joining me today,” he began. 

“You’re not going to do the whole thing, are you?” Crawly interrupted. 

“Thank you for joining me today,” Aziraphale said again, more firmly. “Ah, yes. Humans come in essentially two varieties, as you see here.”

The next glowing screen was a picture of two stylized human bodies, with arrows pointing towards their heads. One said “man” and the other said “woman”. 

“That’s not true,” Crawly objected. “There’s way more varieties than that. There’s plenty of people who don’t fit either of those categories—”

“I know that,” Aziraphale said, testily. “But for the sake of simplicity, we’ll start with these two. As I was saying, these two varieties were designed with interlocking genitalia—”

“Interlocking?” Crawly interrupted again. “From what I’ve seen, nothing locks in anywhere. It’s all slippy slidey, in and out.” He made a hand gesture, and Aziraphale’s face did something strange. 

“I see,” the angel said, enunciating very carefully. “Would interconnecting work better?”

“Yeah I suppose so, if you want to make it sound like woodworking.”

“Crawly!”

“You asked for my feedback, didn’t you?”

Aziraphale sighed and waved his hand, and the next image was an extremely anatomical... something... that reminded Crawly of some of the less pleasant things he’d seen in hell.

“What’s that supposed to be then?”

“It’s a cutaway image that shows what happens when a penis penetrates a vagina–”

“Ahhh stop!” Crawly threw his hands in front of his face. “Aziraphale!”

“Is it too graphic then?” The angel fretfully twisted his hands together.

“In completely the wrong way,” Crawly said. “Ok, fine, keep going, I think I can handle whatever else comes next.”

The next image was a list of dense text that explained in some detail exactly what happened when a sperm fertilized an egg and then how a human embryo grew in utero. In the time it took Aziraphale to read it all, Crawly managed to drink another cup of wine. 

“...and that is how sexual reproduction occurs,” he finally finished. “I wasn’t sure if I should explain childbirth but decided against it.”

There was a long silence.

“Angel,” Crawly said, “what is the point?”

Aziraphale sat down heavily on one of the low bench seats and made one of his wobbly sad faces. “The point? Well, the food presentation went down so well, and Gabriel even sent me a nice letter, and I suppose I just don’t want a repeat of what happened after Sodom and Gomorrah.”

“What happened–” Crawly began to ask but Aziraphale shook his head and frowned.

“It doesn’t matter. Anyway. Obviously you know much more about how all this works than I do. So what do you think I should focus on, if not the anatomical side?”

“Right,” Crawly said, slowly. “Yeah. Well I suppose the question is, what do you think upstairs wants to know?”

Aziraphale considered this, and Crawly tried to watch him sidelong as he thought. The glow of the heavenly presentation on his face suited him, and Crawly was glad—even though he’d just sat through ten minutes of words such as “spermatozoa”, “implantation”, “uterine lining” and “embryonic cell division”—that he’d managed to irritate the angel into letting him inside and sharing a drink with him.

“I think,” Aziraphale said, after a moment, “they want to know why humans have so much sexual congress, and whether it is good or bad, and what we should do it about it.”

“‘Cause they like it, it depends, and nothing,” Crawly said promptly. “There, done.”

“Yes, and I agree with you,” Aziraphale said, which was the sort of comment that Crawly would spend decades of years obsessing over in between their meetings, “but I have to make it compelling! I’m sure sex is very nice, but it’s not something angels go about doing, is it?”

“The Nephilim—”

“Yes the Nephilim, of course, but that was a disaster, and there were so many meetings and memos and reprimands.” He shook his head sadly. “I thought asking the nice people at the temple would help, and the young lady I spoke to was quite happy just to have a chat, and she gave me quite an exhaustive list of how she did her job, but it wasn’t quite enough. I think really need some hands-on experience but of course that’s impossible...” 

Did he, Crawly thought, with a sudden wash of something that made him feel tense and rather odd, just say he wanted hands-on experience? With sex?

Before his brain could catch on, Crawly’s mouth said, helpfully, “We could do it.”

The words fell like stoneware on a hard floor.

“Pardon?” Aziraphale said, his cup poised halfway to his mouth.

“You can’t do it with humans, because of the Nephilim thing, right? And... you can’t do it with another angel, because they’re a bunch of feather-brained twits—” at that Aziraphale looked as if he was about to argue, but Crawly kept talking, rapidly, “—which really only leaves demons, and I’m the only one you’ve got handy.”

Aziraphale looked at him now and Crawly felt something, the faintest hint of what might be called interest coming from the angel. A tiny flicker of... desire. 

“And you wouldn’t mind?” Aziraphale said, very carefully. 

“Sure,” Crawly said, trying not to think about how very hard his unnecessary heart was pounding. “I can pass it off as a temptation, if it comes up downstairs. Not that it will. Long as I get my reports in on time they don't really care what I do.”

Aziraphale swallowed, and Crawly felt the tiny flicker again.

“I suppose it makes sense,” the angel said. “Right now?”

“Unless you’ve got more pressing matters to attend to,” Crawly said, edging along the soft rug of the floor. Aziraphale put his cup down, and nodded, and also moved closer.

 _Right,_ Crawly told himself sternly. _Don’t fuck it up._

* * *

About five minutes later they lay in the middle of the pile of cushions on the floor. Crawly’s eyes were shut, and he found himself regretting almost every single moment of his existence.

“Is it usually over so quickly?” Aziraphale asked, politely. “It seems much longer as an observer.”

Crawly covered his face with his hands, again. “Ok, look, angel. I should probably have mentioned this before we began. But I’ve never... well I had never... not with anyone else, anyway.”

Aziraphale made a surprised noise. “Oh! But you must have!”

Crawly snapped his fingers to get rid of the mess, pulled his tunic down and sat up. “What, because I’m a demon? You think it’s all just nonstop shagging in hell or something?”

“Oh no, of course not! It’s just I thought with all the temptations and so forth... you know... and you’re so very attractive,” Aziraphale said, with utter sincerity, his cheeks going pink.

Ok. So Aziraphale had just given him a handjob (albeit an extremely brief one) _and_ called him attractive, so maybe it wasn’t quite the worst moment of Crawly’s existence so far. Maybe it didn’t even make it into the top five, although Crawly was pretty sure it was going to get worse before it got better, especially as Aziraphale was almost certain to throw him out on his ear any moment now. 

But he didn’t. Instead, he put a cautious hand on Crawly’s shoulder, as if calming a skittish animal. “Perhaps we could, ah, try again?” 

Crawly thought that sounded like just about the worst idea since Lucifer had invited him for a “little chat” but again his mouth moved faster than his brain. “If you want.”

“I’m fairly certain it’s the sort of thing one improves at, with practice,” Aziraphale said, not unkindly. “And... oh! I do have the notes from my meeting with Lahamu at the temple. Lovely girl.”

“Notes,” Crawly said, with a slight hiss. 

He pulled out the scroll he’d been carrying earlier and unrolled it. “Yes, see here, she gave me a list!”

A list. This was going to actually be worse than the first time, which a few seconds ago Crawly would have said was impossible. 

Aziraphale waved the scroll in his direction. “Yes. Look. It says to start with kissing.”

Crawly glanced at the list and noticed only a few words that made him feel hot and possibly even queasy _—oil_ and _ropes_ and _blindfolds_ —before the angel snatched it back and rolled it up again. 

“Do you think we should start with that?” Aziraphale asked.

“With... kissing?” That feeling in Crawly’s stomach intensified, something like nervousness and also anticipation. He’d never really seen the appeal of mushing his eating hole up against anyone else’s, but the angel’s hopeful expression made it impossible for him to say no. “Why not?”

Aziraphale shuffled close enough sthat Crawly felt as though he was about to go cross-eyed, and then there was an awkward moment that lasted far too long, until finally he leaned forward and brushed his lips very gently against Crawly’s, gently and chastely.

“That was nice,” Aziraphale said, quietly. 

“No need to be rude,” Crawly said, and this time he leaned in. Aziraphale’s lips were soft and warm and this close Crawly could smell him, all desert after rain and flowers and honey. He had the urge to open his mouth just a tiny bit and flick his tongue out, and touch it to Aziraphale’s skin, and see if he tasted like that too. 

Aziraphale made a surprised noise and his mouth opened beneath Crawly’s. So he opened his mouth further too, tilting his head the way he’d seen humans do, and then he was licking into Aziraphale’s mouth and Aziraphale was licking back, and it was very strange, and also possibly the best thing Crawly had ever done.

Aziraphale made another of those sounds and Crawly could feel that flicker of interest he’d sensed before from the angel kindle and burst into something bright and warm. One of Aziraphale’s arms pressed around his shoulders and another wound around his waist, and then they were both tumbling down into the cushions again, but this time with their mouths pressed together. 

Crawly wasn’t entirely sure what to do with his hands but decided since he’d always wondered exactly what Aziraphale’s hair would feel like it was worth a shot, (and surely he couldn’t be smited—smitten? smote?—for groping under the current circumstances, which seemed to be entirely about mutual groping), so he reached up and pushed his fingers through the angel’s short hair. 

Aziraphale made another of those noises and Crowley felt encouraged enough to slide one of his legs up along the angel’s hip.

“This is already going better, don’t you think?” Aziraphale said, pulling away from Crawly’s mouth.

“Yeah,” Crawly said, and since his mouth was free he decided to try kissing the angel’s neck. “Maybe the list wasn’t the worst idea.”

“Oh, the list,” Aziraphale had suddenly detached himself and rolled away, and Crawly had to stop himself from whining. He could only hope that wasn’t it for the kissing, because it had been much better than he’d expected. “Ah, here we go. She said she usually moves from kissing to stroking and caressing? Depending on the client, of course. And then mouth-to-genital contact.”

While Crawly’s brain was trying to somehow catch up with that last point— _he means cock-sucking,_ a small voice inside him helpfully said, _maybe he’ll actually put that pretty mouth of his on your cock—_ Aziraphale had rolled the scroll up and turned back to him.

“Shall we?” he asked, and without waiting for an answer, pulled his tunic off. 

It wasn’t really fair that angels were made to be so ... whatever they were... Crawly thought, dimly, as Aziraphale reached for the hem of his robe. None of this was happening the way that he’d imagined it might (and now the angel was considerately helping him get his kit off, he could admit that he’d thought about it before, quite a few times). In those fantasies, Crawly had been confident and seductive, or at least insouciant, but now he was struck silent by an expanse of soft angelic skin, the curve of his shoulders, the sprinkling of hair across his solid thighs, and the frankly surprising size of his prick jutting up against the swell of his belly. 

Crawly wasn’t sure exactly what he wanted to do with all that angelic flesh, but he wanted it so much he was aching. 

Aziraphale tugged the tunic over his head and let it fall, and then settled back. His eyes had gone dark in the shadowed room and he was looking at Crawly with an intensity that Crawly had never seen before. He looked hungry, yes, very hungry. As if he’d not eaten in months, which Aziraphale would never do. It was odd. And also good, because Crawly was the one he was hungry for. The lust pouring off him now was strong enough that Crawly could almost taste it.

“Ah... I... was going to touch you, wasn’t I?” Aziraphale said, his voice low, a blush creeping from his face down his neck. Crawly didn’t trust himself to say anything sensible. Instead, he took Aziraphale’s hand and pressed a kiss against the palm. 

Which was not at all what he’d planned on doing, but he didn’t seem to be in control of any of this. 

Aziraphale made one of those sounds again, and Crawly found himself being pushed back into the cushions with a force he couldn’t have resisted even if he’d wanted to. Aziraphale knelt above him, one hand beside his head and the other gently stroking the side of his face, down his neck, and over the line of his collarbone until his fingertips came to circle one his nipples. Crawly tried very hard not to live up to his name but the sensation made him want to writhe, to arch his back and press himself into Aziraphale’s hand.

Then Aziraphale bent his head and very deliberately put his mouth on Crawly’s other nipple.

It felt like sinking into a very warm bath, having Aziraphale’s hands and mouth all over his body. Verging on unpleasantly good. He was so hard now, again, and he couldn’t help but push his erection against Aziraphale’s soft hip. The angel’s cock rubbed against his own skin in return, leaking wetness against him. 

“You should, you should,” he said, and then couldn’t remember what he was trying to say, because Aziraphale’s wet kiss on his nipple had turned into the graze of teeth. 

Bloody hell, he was supposed to be the tempter, and he was just lying here letting the angel do whatever he wanted. 

“Biting,” he managed to get out, “really?”

“It was on the list,” Aziraphale replied, pushing himself up and looking down with a slightly concerned expression. “Did you not like it? What if you bit me instead?” He tilted his head slightly, as if inviting Crawly to the particular spot where his neck met his shoulder. 

“I suppose I can,” he said, and cautiously, gently nipped at the skin. Aziraphale shuddered against him, and Crawly tried it again, a little harder. Aziraphale gasped and his hips bucked. _Interesting._

He did it again, harder still, and Aziraphale moaned this time, pushing himself against Crawly. So much skin touching skin, and nothing at all like the recreational wanking Crawly had engaged in since he’d figured out how his own body worked a few weeks into his corporeal existence. 

He bit the angel once more, sinking his teeth into the muscle above his collarbone. Not hard enough to break the skin, but hard enough to make Aziraphale rut against him _—_ this was so good, why hadn’t he tried to talk the angel into it centuries ago? 

“Stop, stop!" Aziraphale pulled back, his face flushed. “I think we should try actual penetration, if you’d be amenable.”

What Crawly really wanted was to keep biting Aziraphale some more while he moaned, and also not to hear the word penetration ever again, especially not in this context. But that hot look in Aziraphale’s eyes was overwhelming, and he didn’t want the angel to call the whole thing off, so he nodded. 

“Sure yeah. Do you want to... do me?”

 _Very smooth,_ Crawly thought, but then Aziraphale seemed practically to be seducing himself at this point, and the flare of lust that came from him at Crawly’s words was like the leaping flame from salt in wood. 

“Would you mind?” Aziraphale said, and the bastard actually licked his lips. 

“I volunteered, didn’t I?” 

“Yes you did.” Aziraphale sat back, his knees on either side of Crawly’s hips, cock bobbing up against his stomach in a way that Crawly tried not to stare at. “You know you can tell me stop any time, don’t you?”

“Of course I bloody know that,” Crawly replied, snapping back at the gentleness in Aziraphale’s voice. He was a terrifying demon from hell, not some wide-eyed bride on her wedding night. “Come on, get on with it.” He wriggled in what he hoped was at least a slightly alluring way, and Aziraphale snapped his fingers and was holding a small clay jar, which he set on the floor beside them.

“Oil,” Aziraphale said unnecessarily. “For pen—”

“Don’t say penetration again, I’m begging you,” Crawly said, trying to sound teasing but realizing too late he sounded desperate, as if he was begging for something else. Which he was, in a way. He wanted Aziraphale’s hands and mouth back on him as much as he’d ever wanted anything.

“All right. Move your legs, yes like that,” Aziraphale said, and Crawly lifted his knees up in what felt like the most ridiculous position, but Aziraphale made one of his _this is the most delicious meal I’ve ever eaten_ noises. Then he dipped his fingers in the oil jar and bought his hand in between Crawly’s legs, and pressed a finger against him.

Crawly wasn’t sure if felt good or not. It certainly felt something, and he tried not to tense up as Aziraphale slid his finger inside him. Aziraphale bit his lip, as if concentrating on something difficult.

It wasn’t unpleasant. It was just strange. Not least of all because it was Aziraphale. Fussy, anxious, rule-following _(impatient, impulsive, indulgent)_ Aziraphale. Moving his finger in and out of Crawly’s body. And then he repeated the action except with two fingers, and while the stretch was almost painful, there was pleasure there too, and Crawly’s back lifted up as those fingers brushed against something within him. He choked off a gasp and Aziraphale instantly stopped.

“Keep going!” he barked, rougher than he intended.

“Oh,” Aziraphale said, moving his hand as instructed. “Is that... good?”

“Yeah. You should try it sometime.” _With me._

“Then... Should we... move on? To the ahh...” the angel paused, and Crawly knew he was considering the word penetration and then trying to think of a suitable alternative.

“Fucking?” Crawly suggested helpfully, and enjoyed the slight wince that crossed Aziraphale’s face.

“Yes, fine, that,” Aziraphale withdrew his hand and then shuffled closer on his knees. 

This, Crawly thought, was going to kill him, watching the angel carefully reach for the oil and then position himself. The only sound in the room was the harsh rasp of his own breathing, too habitual for him to consider stopping. 

And then Aziraphale was pushing inside him, and it was far too much, actually burning, and he couldn’t help but make a hiss. 

“Should I _—_ ”

“Just keep going,” he hissed again, and Aziraphale, curse him, did, pushing into Crawly’s body with a carefulness that was almost endearing. As if Crawly was worth being gentle with. 

And then he was inside him, all the way, their bodies flush together, Aziraphale’s hands on his hips, and his expression something like surprise. Or maybe something else, something Crawly couldn’t identify, even though he thought over the last few thousand years he’d memorised every flicker of feeling on that face. 

“Crawly,” Aziraphale said. “That’s... oh. Oh. You. You’re very beautiful.” And he moved his hips in such a way that the burn of it was replaced by sparks of pleasure rushing through Crawly’s whole body.

“Bollocks. Demons aren’t beautiful. Take it back."

“I don’t think I will,” Aziraphale retorted, and moved again, harder this time, and Crawly heard himself moan as if from a very great distance.

“Should I stop?“

“No, just, go harder.”

“Oh,” Aziraphale said, his voice very low now. “Is that what you’d like?’

“Please,” Crawly’s traitorous mouth said, “fuck, hard, hard as you like, please angel, this is good, this is so good, I want you _—_ ”

Thank satan his next words were lost in a gasp as the angel _—_ _my angel_ _—_ was moving, harder and faster, in him _. Inside him._

There was a noise above them, the sound of feathers moving in the air. Aziraphale’s wings were out, curving down around their bodies. Crawly wound his hands around his back and pushed his fingers into the feathers at the junction of Aziraphale’s wings and back, so he had one hand on human skin, the other on ethereal feathers. 

“Crawly, I’m going to _—_ “ Aziraphale said, his hard rhythm giving way to an urgent, rough shuddering. He made a shocked low sound. Then he kissed Crawly again with almost bruising force, one of his hands behind Crawly’s head and tangling into his hair, pulling him harder into the kiss.

His other hand worked between them and curled around Crawly’s cock, and stroked it hard and fast.

Crawly was lost almost immediately in the bright wave of it, sunlight and warmth, coursing through him. It was every good thing a demon definitely didn’t deserve, and he spilled hot into Aziraphale’s hand.

It was probably for the best that Aziraphale was kissing him so hard as he came, otherwise he’d’ve said deeply something regrettable. Something sappy and stupid and ridiculous, something terrifying demons from hell definitely should never say, not even after what had been the best few minutes of their existence. 

Finally, Aziraphale pulled away and they were left staring at each other. Aziraphale was flushed and his hair was sweat-damp and curling against his forehead, and his mouth was very pink. His wings were trembling, slightly, with a faint rustling noise, and Crawly reluctantly pulled his hand back from where his fingers had been buried in his feathers. It didn’t seem like the time anymore. Now it was all a bit awkward and wet and sticky. 

“Ah. Thank you. For your help... with my research,” Aziraphale finally said, easing further away, and breaking their locked gazes to look intently at something on the far wall. Crawly missed him almost immediately. “It was. Rather enlightening.”

“Right,” Crawly said, pushing himself up. He felt boneless and it was hard to remember how his limbs were supposed to work. “I think I can see why humans are so into it.”

“Quite,” Aziraphale said, with a tight and distant smile. One of his hands drifted to his neck and the meaty part of his shoulder, and touched the bite marks Crawly had left there. 

They were distinctively toothy marks, and Crawly thought of him going out into the world tomorrow or the day after with those red on his neck. No-one would know that a demon made that mark, that a demon had done that to an angel. Besmirched his perfect angelic form. Dirtied it up. Corrupted it. Made him gasp and moan and _come._

But Crawly would know. 

Then Aziraphale frowned, and with a miracle, the marks were gone. 

_Right._

“How are you going to write this all up in your presentation then?” Crawly said, and it came out more jeering than he’d intended. 

Aziraphale went an even darker shade of pink, and began hunting around for his tunic.

“I think I shall, ah, focus on the... ah, the, you know, the...” he found the errant clothing and with a shift of his shoulders, his wings were gone, and he pulled the tunic over his head. 

“The bit where you fucked a demon and liked it?” Crawly said, and immediately regretted it, because Aziraphale’s eyes fluttered shut with that same expression of affronted dismay he’d seen so many times again. Crawly should have seen this coming, he really should have known that Aziraphale may have wanted him in the moment, but afterward...

Then Aziraphale opened his eyes again, and gave Crawly a small, cautious smile.

“Yes,” he said. “I suppose I very much did.” 

_Oh._

“Yeah. Me too.” Crawly said, idiotically, like an idiot. “But. You know. I was thinking. We hardly made any progress on your list. So. Any time you wanted to do it again. I could do it. Again. You know. For research of my own. How to be a better tempter. That sort of thing.”

Aziraphale’s smile was broader now, and then, shockingly, he reached over and took Crawly’s hand in his own, lacing their fingers together. 

“Certainly,” he said. “And I’ll need to know how exactly to foil your temptations. Yes. This is a whole new avenue of research we mustn’t neglect. There are so many areas to explore. With the research, that is. And it’s very important to be very thorough. When one is researching.”

And Crawly’s stupid, not-at-all-human but still deeply hopeful heart gave a terrible kick in his chest.

* * *

A few weeks later, in heaven’s third best boardroom, the Principality Aziraphale, Guardian of the Eastern Gate, launched his celestial Powers-Point-To-The-Glory-Of-God presentation. 

He coughed, nervously. 

“Welcome, my esteemed colleagues,” he said. “Today’s presentation is called ‘A complete beginner’s guide to understanding human sexual behaviour’.”

The angelic faces of his audience gave him their best impression of perfect rapt attention. Except Gabriel, who simply seemed bored.

“I originally intended to give you a full anatomical explanation of human sexual activities,” Aziraphale continued, “but I rather feel that if anyone is interested in such detail, they can access the blueprints from the files pertaining to the Creation Phase of the Human Project. Instead, after my research so far, I would like to show you my conclusions.”

He waved his hand, and his second, and only other slide appeared.

“Humans have sex because they like it. It can be both good and bad, depending on the circumstances, and I propose in the absence of harm, we simply should leave them to it.” He clasped his hands behind his back to stop himself from worrying at his robes. 

There was a long stretch of silence.

“Any questions?” He added, hoping the tremor in his voice wasn’t audible to anyone else.

Uriel spoke first. “What do you mean, because they like it?” 

“My research,” he knew his face was reddening, but he continued, trying very hard not to think about exactly what his research had entailed. “Indicates that sexual activity can be very pleasurable. It is not just for procreation alone.”

Uriel frowned. “I’ve seen the pictures, Principality. How can _it_ possibly be pleasurable?”

Aziraphale nodded, resisting the urge to loosen his bow tie. “Good question. You see, it’s all to do with... nerve endings, and stimulation, and ah, the basic design of the human body.” He struggled to think of an analogy that wouldn’t sail over their heads. “It feels nice. Very nice. It’s rather like–or so I am led to believe–the sensation of having done one’s duty to one’s angelic colleagues in a perfect manner and having then received a commendation.”

There was a murmur among the crowd, and some nods. 

Gabriel raised a hand. “I have a question. When you say ... leave them to it? What is exactly you’re proposing?” He frowned at Aziraphale in that way, which always made him feel rather like a small bug about to be stomped on by a large foot.

“I propose that if the humans in question are consenting, and their activities do no harm to others, that we do not concern ourselves with sexual activity at all.”

“But,” it was Sandalphon, and Aziraphale did his best to conceal any trace of emotion on his face. “You said it was nice. Isn’t everything nice actually bad?”

There was another murmur of agreement, and he saw Michael nodding sternly.

“Not at all,” Aziraphale said when the whispering died down. “Is enjoying the warmth of sunlight bad? Is the taste of perfectly ripe fruit bad? Is it bad to have a conversation with a trusted friend? Is it bad to enjoy to a well-told story?”

He could tell by the puzzled looks the angels were giving each other that they had no idea what he was talking about.

“There is nothing inherently bad, for the humans, in nice things,” he continued. “And. Well. So too with love. Loving others is not inherently wrong. If I can quote one of our ongoing projects ‘whoever lives in love lives in God, and God in them’.”

Uriel had her hand up again. “So you’re saying this sexual intercourse business...” she wrinkled her nose, as if she’d caught the scent of something distasteful, “is an act of love?”

Aziraphale again tried very hard not to think of anything in particular. Not the way Crawly had arched under his hands, gasped at his touch. “Indeed.”

There was more murmuring and whispering from the crowd of archangels and seraphim. Gabriel steepled his fingers and sighed.

“Since you are the ‘expert’,” he began, in a tone that suggested he very much thought the opposite, “We’ll defer to your opinion in this matter. For now.”

“Thank you.”

“But,” Gabriel waved a hand towards him, dismissively. “Keep us informed. If anything comes up with your research.”

“Ah. Yes. My research. Plenty more of that to get on with,” Aziraphale said, blankly as he could. “Never an end to it.”

Gabriel rolled his eyes. He didn’t even try to conceal how irritating he found Aziraphale any more. “Right. Off you go.”

“Toodle pip,” Aziraphale said, and he left the boardroom without a backward glance.

Then he took the celestial escalator back to Earth, absolutely, completely and utterly not thinking at all about research.

**Author's Note:**

> Yes I am a sucker for this trope, so I made another cake. Inspired Summerofspock’s [Ideal Partner](https://archiveofourown.org/works/20186170/chapters/47829721), Fyre’s [Anatomy 101](https://archiveofourown.org/works/21358426/chapters/50873446) and of course Entanglednow’s A Measure of Success. (Poor confused supernatural beings.)  
> [Come yell at me on Tumblr.](https://antikate.tumblr.com/)


End file.
